The operation last week targeted 69 homes and businesses across Germany and in Bosnia, Switzerland, France, the Netherlands, Lithuania and Russia, said German federal police and Frankfurt prosecutors.

The suspects allegedly used so-called darknet systems -- or encrypted peer-to-peer networks -- to sell heroin, cocaine, cannabis, amphetamines, ecstasy as well as forged German, Dutch and Italian identity documents, they said in a statement.

The German security services called the raids and arrests "a major blow against the German-speaking underground economy and further proof that there is no complete anonymity on the Internet, including in the so-called darknet".

Police in the raids last Tuesday and Wednesday confiscated servers in France, the Netherlands, Lithuania and Russia as well as numerous PCs and storage media, a firearm, illegal drugs and 150,000 euros ($163,000) in cash and assets.

The gangs had also traded in stolen credit card and online banking data, and hacked access names and passwords to various Internet services.

They further offered criminal services, such as the infection of computers with malicious software, police said.

The suspected technical administrator of three networks was a 27-year-old Bosnian national, who was arrested by the local police organised crime squad and the High Tech Crime Department Republika Srpska.

German police arrested a 22-year-old German national who ran a trading platform that sold illegal drugs, and Syrian brothers aged 19 and 28 after finding 36 kilogrammes (79 pounds) of amphetamine, 1.5 kg of cocaine, 2 kg of hashish and 2.3 kg of ecstasy pills in their apartment.

They also arrested two German men aged 29 and 21. The younger suspect was the alleged administrator of two networks and also offered an illegal streaming platform for pirated movies and sports shows.

The statement did not specify who the other three arrested suspects were.